The present invention relates to an endoscopic treatment tool which is passed into or out of a treatment tool insertion channel in an endoscope in order to remove and retrieve polyps in body cavities and perform other treatments.
Endoscopic treatment tools are generally comprised of a flexible sheath that is to be passed into or out of a treatment tool insertion channel in an endoscope, a manipulating wire that is passed through the flexible sheath in such a manner that it can be moved back and forth along the longitudinal axis thereof, and a treating member that is coupled to the distal end of the manipulating wire and which is allowed to eject from or retracted into the distal end of the flexible sheath by remote control from the proximal end.
If a plurality of polyps are found in a body cavity, a high-frequency snare is first inserted into an endoscope and one polyp is removed with it, which is then slipped out of the endoscope, leaving the polyp in the body cavity; thereafter, a foreign matter collecting tool is inserted into the endoscope and the removed polyp is scooped with the tool and taken out of the body cavity before another polyp is removed with the snare. However, it is cumbersome to alternate the high-frequency snare with the foreign matter collecting tool in the steps of insertion into an endoscope and removal from it. With a view to eliminating this problem, it has been proposed in U.S. Pat. No. 5,741,271 that a plurality of treating members including a high-frequency snare loop and a foreign matter retaining or capturing basket should be provided at the distal end of a single flexible sheath so that polyps can be both removed and collected with a single treatment tool.
The prior art endoscopic treatment tool disclosed in U.S. Pat. No. 5,741,271 is so designed that both the high-frequency snare loop and the foreign matter retaining basket are protruded from and retracted into the flexible sheath via an opening provided at the distal end of the flexible sheath. If a polyp removed with the high-frequency snare loop is retained in the basket, the basket will interfere with the high-frequency snare loop, making it impossible to remove another polyp.
To remove the next polyp, the treatment tool must first be slipped out of the endoscope, the already removed polyp is taken out of the basket and the treatment tool is reinserted into the endoscope. This procedure is no less cumbersome than in the case of using a plurality of treatment tools.